A few things to consider, Use any prop that will bolt to the shaft. Use water proof grease in the flex shaft housing. Try convert the handle into the transom bracket. The handles are usually adjustable to slide up and down the shaft ....... keep this option as the biggest concern you will have once you make it work will be prop depth. If the prop runs too deep you will get a lot of cavitation ( no speed ) ..... shallow is what you want. You should be able to adjust the vertical height with the handle and the prop angle by tilting the engine. Also convert the exhaust with a tube that reaches under water ....... now that's quiet!!!!!! The only thing you can't really fix is the fact weedeater motors are meant to run at full throttle like chainsaws ...... but it will still work, just a little hard to control your speed. Good Luck - let us know how you make out.